Window regulators which support a slider base, to which a window glass is fixed, in a manner to allow the slider base in the longitudinal direction of a guide rail and which make the window glass move up and down by pulling wires are widely used in vehicles. The slider base has guide portions which are slidably engaged with the guide rail. A pair of wires are routed along the guide rail to pull the slider base in the forward and reverse directions, and ends of the wires are respectively engaged with wire engaging portions provided on the slider base. Pulling the wires causes a force in the raising/lowering direction to act on a force application portion on the slider base to move the slider base.